Change the type of return value of profile_count::value to uint64_t

Change the type of return value of profile_count::value to uint64_t

The field in which profile_count holds the count has 61 bits but the
getter method only returns it as a 32 bit number.  The getter is (and
should be) only used for dumping but even dumps are better when they
do not lie.

gcc/ChangeLog:

2021-07-13  Martin Jambor  <mjambor@suse.cz>

	* profile-count.h (profile_count::value): Change the return type to
	uint64_t.
	* gimple-pretty-print.c (dump_gimple_bb_header): Adjust print
	statement.
	* tree-cfg.c (dump_function_to_file): Likewise.